The Senate is expected to take a procedural vote Wednesday to advance a bill passed by the House that funds the government through Dec. 15 but defunds the Affordable Care Act. It could take until Sunday for Senate Majority Leader Harry Reid (D-Nev.) to do it, but in the end it appears he has the votes to strip out the health care provision.

That means the Senate is on course to send a clean spending bill back to the House — where conservatives are itching to kill Obamacare — possibly with less than 48 hours on the clock before a government shutdown.

Sens. Ted Cruz of Texas and Mike Lee of Utah are trying to get fellow Republicans to unite behind a strategy of denying Democrats the 60 votes they would need to end debate on the bill, which would prevent Reid from stripping out the Obamacare defunding language by a majority vote.

“In my view, every Senate Republican should stand united and support the House Republicans. Any senator who votes for cloture on the bill … is voting to allow Harry Reid to fund Obamacare with just 51 votes,” Cruz told reporters. “I think that should pose an easy choice to every Republican senator.”

“It would not be an acceptable option if the majority leader were to decide to use a procedural trick to allow only one amendment, an amendment that would gut the House-passed continuing resolution,” Lee said.

But that effort appeared to lose steam after spokespeople for Senate Minority Leader Mitch McConnell (R-Ky.) and GOP Whip John Cornyn, Cruz’s fellow Texan, said they won’t back that approach. Aides for both leaders said neither senator would oppose procedural votes on a bill that defunds Obamacare.

“Sen. McConnell supports the House Republicans’ bill and will not vote to block it, since it defunds Obamacare and funds the government without increasing spending by a penny,” said McConnell spokesman Don Stewart of the House-passed CR that is set at a $986 billion yearly spending level.

The Senate opened Monday in a nasty fashion with Reid denouncing conservatives as “anarchists” and “fanatics.” He was quickly followed by Cruz, who momentarily blocked the Nevada Democrat from moving to consideration of noncontroversial nominees.

Cruz came back to the floor two hours later to ask that the Senate unanimously approve the House-passed spending bill that defunds Obamacare without voting on any amendments, which prompted an objection from Reid. Cruz then asked that a future attempt by Reid to strike the Obamacare defunding language be subject to a more onerous 60-vote threshold rather than a majority vote. Reid objected to that too.

“The Senate rules set up a lot of hurdles. That’s the way precedents have been developed over the years,” Reid said in dismissing Cruz’s requests. “Senators have enough 60-vote hurdles.”

Cruz quickly sought to paint Reid as backing a government shutdown by denying immediate House passage of the government funding bill.

“Five minutes ago the Senate could have prevented a government shutdown,” Cruz said. “He is willing to risk a government shutdown. He is willing to force even a government shutdown in order to ensure that Obamacare is funded.”

The exchange underscores the bad blood between Cruz and Reid and the high stakes countdown to an Oct. 1 government shutdown: Both want to keep the government open, but the Texas freshman wants to do so only if the CR is preserved as passed by the House and does not fund Obamacare, while Reid seeks to keep President Barack Obama’s signature health care law fully funded. Anything less is “dead” in the Senate, Reid said.

“We’re not going to bow to tea party anarchists who deny the mere fact that Obamacare is the law. We will not bow to tea party anarchists who refuse to accept that the Supreme Court ruled that Obamacare is constitutional,” Reid said in a blistering opening speech. “The simple fact remains: Obamacare is the law of the land and will remain the law of the land as long as Barack Obama is president of the United States and as long as I’m Senate majority leader.”

Sen. Marco Rubio (R-Fla.) said Monday he would support Cruz’s approach, as did several other conservative senators like David Vitter of Louisiana and Mike Enzi of Wyoming.

“A vote for cloture will make it easier for Senate Democrats to preserve this job-killing law,” Rubio, a tea party favorite, said in a statement. “That is why I will vote no on the motion to cut off debate.”

But Sen. John McCain (R-Ariz.) said Republicans’ energy would be better spent forcing Democrats into tough votes on amendments to the CR, like a repeal of the medical device tax. McCain said he will vote with McConnell and Cornyn not to block the bill.

“In my view a better strategy would be to try to get amendments up that force tough votes,” McCain told reporters.

Reid said Cruz and Lee are promoting a “Thelma and Louise-style” tactic.

“If Democrats don’t bow to every demand they have, they want to go right over the cliff. We are not going to go with them,” Reid said.